Recently Chepicap reported on an outage that hit the Stellar network on May 15th, due to several of the validating nodes going down simultaneously. Now, Ripple CTO David Schwartz has admitted that the same type of outage could effect the Ripple Network.

As a response to criticism over the shutdown, The Stellar Development Foundation posted a Medium blog in which they explained what happened and why. It is discussed how Stellar didn't fail, it acted as intended. When enough validators disappear from the network, the system shuts down to avoid the possibility of a fork. From the blog:
"The halt wasn’t because Stellar’s Consensus Protocol failed — in fact, it worked as intended. For a system like Stellar, a temporary halt is preferable to the permanent confusion of a fork. But yesterday shows that Stellar needs better tooling around uptime. We need better status monitoring for validators, and it needs to be easier to restart a validator after it goes down.
We’ve seen claims that Stellar is “over-centralized” and that somehow a failure with SDF’s nodes dragged down the whole network. Ironically, the opposite is true. Stellar has added many new nodes recently. In retrospect, some new nodes took on too much consensus responsibility too soon. We need better community standards around maintenance timings, quorumset building, and validator configuration."
Afterwards, Ripple CTO David Schwartz took to twitter to say that he felt that Stellar explained themselves well:
He went on to admit that the same thing could happen with Ripple, because preventing a fork is the top priority, though perhaps more work needs to be done:
Therefore it is important for readers to know that this is a safety feature for the integrity of the blockchain, not a bug. Whether there is a better way to handle the situation is for the developers to figure out. In the meantime, stick with Chepicap for all updates on any blockchain outages!